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Doping is an essential approach to enhance the electrical properties of 2D materials. In the present study, two-stage process was used to obtain potassium-doped (K-doped) MoS2. The MoS2 films were grown by magnetron sputtering technique and followed by doping process employing CVD method. The influence of KOH molarity and annealing time on the structural properties of the MoS2 films was investigated thoroughly. 0.2–0.8-M KOH was used to obtain K-doped MoS2. The increase in the molarity of KOH caused a shift in the optical band gap from 1.98 to 1.81 eV. It was observed that increasing the KOH molarity resulted in the loss of homogeneity in the MoS2 films, the use of 0.2-M KOH for the growth of K-doped MoS2 exhibited the most promising results according to performed analyzes. In addition, annealing time also played a critical role in the growth of K-doped MoS2. The dwell times of 5, 10, and 15 min were also used and the effect of molarity and dwell times was investigated. The optical band gap was also shifted from 1.9 to 1.71 eV with increasing the dwell time of KOH. Longer annealing times resulted in the deterioration of the MoS2 film structure. Consequently, an annealing time of 5 min was found to be the optimum value for the growth of K-doped MoS2 film. Overall, this study demonstrates that successful growth of high-quality and homogeneous K-doped MoS2 films which can be employed for various optoelectronic applications. [ABSTRACT FROM AUTHOR]

Aluminum-doped zinc oxide (AZO) is one of the most popular transparent conducting oxide layers that can be employed in many optoelectronic applications in particular in photovoltaic devices due to being a low-cost and nontoxic material. In this study, we report on the effect of deposition pressure and substrate temperature on the properties of AZO films and solar cell performance by employing the optimized films. This study consists of two stages, the first of which concerns the optimization deposition pressure while the second is the substrate temperature of AZO films by evaluating the structural, optical, and electrical properties of the films. The deposited AZO thin film under 10 mTorr deposition pressure exhibited high optical transmission (89.9%), low electrical resistivity (9.1 × 10−2 Ω.cm), and high carrier concentration (3.74 × 1019 cm−3) among the others. The impact of substrate temperature was then investigated using this deposition pressure at room temperature, 150, 200, and 250 °C. The deposited AZO films at 150 °C temperature were found to possess the highest optical transmission (91.1%), lowest resistivity (9.9 × 10−4 Ω.cm), and highest carrier concentration (1.1 × 1020 cm−3) values. Hence, the 10 mTorr deposition pressure and 150 °C substrate temperature were selected as the optimum growth parameters to obtain AZO films, which were then employed in the cell structure. It was, thus, revealed that utilizing AZO films in silicon-based solar cell using such parameters led to the enhancement in the cell efficiency. [ABSTRACT FROM AUTHOR]

We have previously investigated electromyographic (EMG) and transcranial motor evoked potential (MEP) abnormalities after mechanical spinal cord injury. We now report thermally generated porcine spinal cord injury, characterized by spinal cord generated hindlimb EMG injury activity and spinal cord motor conduction block (MEP loss). Electrocautery (EC) was delivered to thoracic level dural root sleeves within 6-8 mm of the spinal cord (n = 6). Temperature recordings were made near the spinal cord. EMG and MEP were recorded by multiple gluteobiceps intramuscular electrodes before, during, and after EC. Duration of EC was titrated to an end-point of spinal motor conduction block (MEP loss). In 5/6 roots, ipsilateral EMG injury activity was induced by EC. In 4/5 roots, EMG injury activity was identified before MEP loss. In all roots, a minimum of 20 s EC and a temperature maximum of at least 57 °C at the dural root sleeve were required to induce MEP loss. Unexpectedly, conduction block was preceded by an enhanced MEP in 4/6 trials. EMG injury activity, preceding MEP loss, can be seen during near spinal cord EC. Depolarization and facilitation of lumbar motor neurons by thermally excited descending spinal tracts likely explains both hindlimb EMG and an enhanced MEP signal (seen before conduction block) respectively. A thermal mechanism may play a role in some unexplained MEP losses during intraoperative monitoring. EMG recordings might help to detect abnormal discharges and forewarn the monitorist during both mechanical and thermal injury to the spinal cord. [ABSTRACT FROM AUTHOR]

Habitual or recurrent dislocation of the patella in the skeletally immature patient is a particularly demanding problem since the etiology is frequently multifactorial. The surgical techniques successfully performed in adults with patellar instability may risk injury to an open growth plate if applied to children. We present a technique that preserves femoral and patellar insertion anatomy of medial patellofemoral ligament (MPFL) using a free semitendinosus autograft together with tenodesis to the adductor magnus tendon without damaging open physis on the patellar attachment of MPFL. A 3-cm long longitudinal skin incision is performed 10 mm distal to the tibial tuberosity on the anteromedial side. The semitendinosus tendon is harvested with the stripper. The semitendinosus tendon is placed on a preparation board and cleaned of muscle tissue. The usable part of the tendon should be at least 20 cm long and 4 mm wide. The two free ends of the graft are sutured with Krakow technique. A medial longitudinal incision 2 cm in length is made to expose the MPFL and to abrade the patellar attachment of vastus medialis obliquus. The first patellar tunnel is created with 4.5 mm drill at the mid aspect of the medial patella in the anteroposterior and proximal-distal direction. The drill hole is formed parallel to the articular surface of the center of the patella. The second tunnel is created with 3.2 mm drill and the entry point is localized at the center of the patella. These two tunnels intersect to form a single tunnel. The semitendinosus autograft is run through the bone tunnel in the patella. Double-stranded semitendinosus autograft is placed in the presynovial fatty plane between the second and the third layer of the medial retinaculum, and tenodesis to adductor magnus tendon is applied by a moderate medial force with the knee flexed at 30°. Aftercare includes immobilization of the joint limited to 30° flexion using an above-knee splint for 2 weeks. No recurrent dislocation was observed in three patients (4 knees) at a mean follow-up time of 17.7 months. Both range of motion and radiological finding were restored to normal limits. [ABSTRACT FROM AUTHOR]

Pedicle screws are placed using pilot holes. The trajectory of pilot holes can be verified by pedicle sounding or radiographs. However, a pilot hole alone does not insure that the screw will follow the pilot hole. No studies have characterized the risk of misalignment of a pedicle screw with respect to its pilot hole trajectory. The objective of this study was to measure the misalignment angles between pedicle screws and pilot holes with or without tapping. Six human cadaveric thoracic spines were used. One hundred and forty pilot holes were created with a straight probe. Steel wires were temporarily inserted and their positions were recorded with CT scans. The left pedicles were tapped with 4.5 mm fluted tap and the right pedicles remained untapped. Pedicle screws (5.5 mm) were inserted into the tapped and untapped pedicles followed by CT scans. The trajectories of pilot holes and screws were calculated using three-dimensional vector analysis. A total of 133 pilot holes (95%) were inside pedicles. For the untapped side, 14 out of 68 (20%) screws did not follow the pilot holes and were outside the pedicles. For the tapped side, 2 out of 65 (3%) did not follow and breached the pedicles. The average misalignment angles between the screw and pilot hole trajectory were 7.7° ± 6.5° and 5.6° ± 3.2° for the untapped side and tapped side, respectively ( P < 0.05). Most pedicle screws had lateral screw breach (13 out of 16) whereas most pilot holes had medial pedicle breach (6 out of 7). Tapping of pilot holes (1 mm undertap) helps align pedicle screws and reduces the risk of screw malposition. Although most pedicle screws had lateral breach, the risk of medial pedicle breach of the pilot holes must be recognized. [ABSTRACT FROM AUTHOR]

Single level axial lumbar interbody fusion (AxiaLIF) using a transsacral rod through a paracoccygeal approach has been developed with promising early clinical results and biomechanical stability. Recently, the transsacral rod has been extended to perform a two-level fusion at both L4–L5 and L5–S1 levels (AxiaLIF II). No biomechanical studies have been conducted on multilevel fusion using the AxiaLIF technique. In this study, the biomechanics of L4–S1 motion segments instrumented with the AxiaLIF II transsacral rod was evaluated. Six human cadaveric lumbosacral spine segments from L4 to S1 were used (age ranges 46–74 years). Unconstrained and non-destructive pure moments in axial torsion, lateral bending, and flexion extension were applied to each specimen following intact, standalone AxiaLIF II, and AxiaLIF II with two posterior fixation options: facet screws and pedicle screws with rods. Range of motion was calculated from the raw data collected with an optical motion tracking system. The two-level transsacral rod was successfully inserted in all the specimens. At L4–L5 level in axial torsion (AT) and flexion extension (FE), none of the surgical treatments showed statistically significant difference between the procedures (all P > 0.05) although facet screws and pedicle screws had higher stability on average. In lateral bending (LB), the two posterior fixation techniques had significantly higher construct stability ( P < 0.05) than the standalone rod. No significant difference was found between facet screws and pedicle screws ( P = 0.821). At L5–S1 level in AT and LB, none of the surgical treatments were found to be statistically significant (all P > 0.05). In FE, standalone two-level transsacral rod had significantly higher range of motion (ROM) compared with the posterior fixation techniques ( P < 0.05). In conclusion, the standalone rod reduced intact ROM significantly. Supplementary fixations including facet screws and pedicle screws are required to achieve higher construct stability for successful fusion. Further clinical studies are essential to evaluate the practical success of this technique. [ABSTRACT FROM AUTHOR]

Hemangioma or vascular malformation of the synovium is rare and presents a difficult problem in diagnosis and treatment. A long history of joint pain and recurrent non-traumatic hemarthrosis usually draws attention to the hemangioma of the knee joint. The lesion can be seen in two different formations; the synovial hemangioma or the arteriovenous malformation named as hemangiohamartomas, both of which involve the synovium and cause non-traumatic episodes of hemarthrosis. MRI scanning together with arthroscopy is a diagnostic tool to demonstrate the extent and the nature of the lesion. We treated the three patients at different ages. All patients underwent standard radiographic examination, CT scans, MRI and diagnostic arthroscopy. After frozen section taken via arthroscopically, the lesions were excised by arthrotomy. The mean follow-up was 38 months (31–45) and all patients are asymptomatic postoperatively. Three additional cases and a review of the literature are presented because of the rarity of the lesion. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate arthroscopically the type, localization and prevalence of the meniscal and chondral lesions accompanying complete rupture of the anterior cruciate ligament (ACL) in patients who elected not to restrict their daily activities after the initial trauma. The size of the chondral lesions was also evaluated. Our second aim is to analyze the effects of age, time from injury, and both age and time from injury in the presence or absence of accompanying lesions in these patients. The localization and type of the accompanying lesions of 317 knees with complete rupture of the ACL were recorded by the same observer. We applied therapeutic arthroscopy to all patients after their first visit to our clinic. All of the patients were military personnel and their history revealed that they had elected to not restrict their occupational activities after the first trauma causing ACL insufficiency. We defined the first 6 week period after the initial trauma as the acute, 6 weeks to 12 months as the subchronic and 12 months or longer as the chronic period. The average time from injury to arthroscopy for these patients, who were all male, was 19.4 ± 20.3 months. Eighty-one percent of the patients had at least one meniscal tear, and 45.1% had at least one chondral lesion. The mean ages at the time of surgery of patient groups with or without medial and lateral menisci lesions were compared, and no statistically significant difference was determined. In the chronic period, the relative risk (RR) values of meniscal tears were 7.75 for medial and 2.40 for lateral. The group consisting of patients with chondral lesions was compared with the group of patients without chondral lesions in terms of their ages and the time from injury to arthroscopy, and the difference was statistically significant. The RR value for patients with co-existence of at least two lesions was 1.761 for more than 30 years of age. The RR values for at least two lesions were 2.356 for the subchronic and 14.909 for the chronic group when compared to the acute group. The RR values in patients more than 30 years of age in the chronic group were 13.58 for medial meniscus, 3.21 for lateral meniscus and 71.88 for chondral lesions when compared to patients less than 30 years of age in the acute group. It is important to note that the combined effects of advanced age and prolonged time from injury in patients who elected to not restrict occupational activities are more severe due to the increase in the occurrence of intraarticular lesions accompanying ACL insufficiency as compared to their separate effects. [ABSTRACT FROM AUTHOR]

Pantibial ligamentous injury including knee dislocation and tibiotalar joint subluxation is an uncommon severe rotational injury. A 21-year-old male injured his right knee falling from a motorcycle. Physical examination revealed effusion on the right knee and ankle, and posterior translation of the tibia as well. The MRI of the right knee and ankle demonstrated the following findings: a complete disruption of cruciate ligaments, the medial collateral ligament, posteromedial corner injury together with a peripheric tear in the medial meniscus, the ruptured deltoid ligament, ankle syndesmosis space widening (>5 mm) and lateral subluxation of talus. Deltoid ligament of the right ankle was repaired and ankle syndesmosis was fixed with a cortical screw. The PCL and ACL were reconstructed arthroscopically with autogeneous bone-patellar tendon-bone graft. The midsubstance tear of MCL, posteromedial corner and medial meniscus tear were primarily repaired with nonabsorbable sutures. 3 years after the surgery, the patient was called for the final examination. MRI and X-ray findings of the knee and ankle joint demonstrated the continuity of ACL, PCL, MCL, and deltoid ligament. The patient, who is a farmer, can go back to his job and perform his daily activities. We presented a previously unreported case that involves both simultaneous occurrence of knee dislocation and tibiotalar joint subluxation. We used the term “Pantibial ligamentous injury” for this case. [ABSTRACT FROM AUTHOR]